The application concerns materials for self assembled (SAM) charge injection layers on electrodes of organic electronic devices. The materials comprise an anchoring group, such as a thiol, a spacer group selected from nitrogen aromatic heterocycles and aromatic rings substituted with an amine, and an electron withdrawing (EWG) group, such as tetrafluorotetracyanoquinodimethane (F4TCNQ), hexaazatriphenylene (HAT) and hexaazatriphenylene hexacarbonitrile (HATCN). The spacer group is connected to the EWG via a single bond from a nitrogen of the spacer group to a mehtylidenyl group of the EWG.